This invention relates to a method of eliminating carbon material by chemical vapor reaction.
Recently, a process for forming carbon films having a very high hardness has been developped utilizing chemical vapor reactions. An example is described in Japanese Patent Application No. sho56-146936 filed on Sept. 17, 1981. Carbon films of this type are very useful due to their high hardness providing a smooth and corrosion-proof surface. These advantages, however, make etching become difficult on the other hand, while etching process is very important particularly in the semiconductor device manufacture.
Particularly, when a substantial thickness of carbon coating is deposited on a substrate, the inside surface of the reaction chamber and the substrate holder are also covered with the carbon material. The carbon material tends to fall as flakes onto the surface of the substrate to be coated and make the substrate inacceptible.